The present invention relates to substrate cleaning apparatus, and in particular, to substrate cleaning apparatus which allows a simple and effective scrubbing-away of particles adhering to an end face and/or a bevel face of a substrate, such as a semiconductor substrate, a glass substrate or a liquid crystal panel which requires a high degree of cleanliness.
In recent years, as semiconductor devices have been more densely packed, wiring in circuits on semiconductor substrates have been more highly-integrated and the distance between wires has been reduced. Especially in optical lithography with a distance between wires not greater than 0.5 μm, a high degree of flatness is required on the image forming plane of a stepper due to a shallow focal depth. Further, if there is a particle of a diameter greater than the distance between the wires on the substrate, it may cause a problem such as a shorting between the wires or the like, and therefore, it is important in substrate processing to achieve cleanliness as well as planarization. Such circumstances may be common to a process for processing glass substrates used for masks and the like or substrates used for liquid-crystal panels and the like. These requirements have given rise to the need for a cleaning technique to remove sub-micron particles from the semiconductor substrate or the like.
For example, as a method for achieving a high degree of cleanliness for a polished semiconductor substrate, a variety of methods have been suggested including scrub cleaning, in which a cleaning body composed of brush, sponge or the like is rubbed on the substrate; and a cavitation-jet cleaning in which a high pressure liquid (a high speed jet flow) is injected toward the substrate to generate air-bubbles by cavitation in order to clean the substrate.
However, there is a problem associated with the above-described prior art in that, although a surface of a substrate can be cleaned to a high degree of cleanliness, the end face and/or the bevel face of the substrate cannot be cleaned efficiently, and as a result, those particles that have not been removed and remain on the end face and/or the bevel face of the substrate would be stuck on the surface of the substrate.